The present disclosure generally relates to radio frequency (RF) detection and ranging (RADAR) and, more particularly, to providing surveillance information about interior spaces where radar is ordinarily not applicable such as the interior of metal cargo containers.
Portable, hand-held radars have been used for detection of hidden objects, e.g., objects such as weapons hidden behind a wall of a building. Some portable, hand-held radar units are capable of discriminating living individuals from inanimate objects and detecting whether an individual may be carrying an object of interest such as a concealed weapon or an improvised explosive device (IED). Such technology may be useful in situations where surveillance of an inhabitable area from behind a surface—such as a building wall, block wall, construction fence screen, boundary fence, or other non-electrically shielded obstruction—may be desired. Some examples include detecting illegal activities such as smuggling or illegal border crossings or, for example, detecting the presence of hostile individuals in a war zone or terrorist situation. In some situations, e.g., police work, military combat scenarios, fire and rescue situations, or border and immigration control, it may be desirable to be able to detect living individuals, and various objects that may be in their possession using a portable, hand-held or other widely deployable radar system from outside any kind of structure occupied by the individuals, for example, a building, temporary shelter, or vehicle. Such portable, hand-held radars may not be applicable, however, for interior spaces that are electrically shielded from a radar unit at the exterior, such as a metal shipping container, metal semi-trailer rig, or metal or carbon fiber aircraft fuselage, for example.